Chetput lake is a lake spread over 15 acres in Chetput, Chennai, India. It is located to the north of Chetput Railway Station. It is the only existing lake at the centre of the city.

Of the total area of the lake, the waterbody is spread across nearly 9 acres. An anglers club was functioning till the 1940s in the lake, whose members visited the small island in the midst of the waterbody for fishing.

Although not used for drinking purposes, the lake was a source of groundwater recharge for the surrounding areas. As the water quality is not saline, the lake has a few varieties of fishes such as rohu, catla and mrigal. Breeding is monitored to assess the water quality.

In recent years, the lake has been heavily encroached upon, particularly near the Chetpet railway station. There have been many plans to rejuvenate Chetpet lake since the mid-1990s, including developing a boat club, an aquarium, seafood stall and fish court besides a walkway around the waterbody. The last attempt to save the lake was in 2005, when the state environment department identified it along with 12 other lakes of Greater Chennai area for an eco-restoration project. The CPR Environmental Education Centre conducted a detailed survey, and based on that, the state government appointed the Tamil Nadu Urban Infrastructure Finance Services Limited to prepare a project report. The State government had sanctioned 4 million to clean the overgrown water hyacinth and desilt the lake in 2007-2008. A building to house a stall of the Fisheries Development Corporation is also coming up by the side of the lake.

Chetput (Tamil: சேத்துப்பட்டு) (aka Chetpet) is a locality in Chennai. It is served by Chetput station in the Beach-Tambaram line of Chennai Suburban Railway. Chetput has a picturesque pond between the Chetput railway station and the Poonamallee High Road, one of the last surviving natural water bodies in the city. It is the locality in Chennai where the mathematician Ramanujan died^{[citation needed]}.

Along with Egmore and Nungambakkam, Chetput is considered one of the original villages merged by the British to form Chennai.

The area is named after Namperumal Chettiar, the building contractor and philanthropist who lived in the mid 19th century.

Until recently, the waters of Chetput lake supplied groundwater recharge for the surrounding neighbourhoods.

Chetpet is located at the center of Chennai, not far from Egmore railway station. CMBT is 8 km from Chetpet.

Chetput village, c. 1905

Transport in Chennai

A lake is a body of relatively still fresh or salt water of considerable size, localized in a basin, that is surrounded by land apart from a river, stream, or other form of moving water that serves to feed or drain the lake. Lakes are inland and not part of the ocean and therefore are distinct from lagoons, and are larger and deeper than ponds. Lakes can be contrasted with rivers or streams, which are usually flowing. However most lakes are fed and drained by rivers and streams.

Natural lakes are generally found in mountainous areas, rift zones, and areas with ongoing glaciation. Other lakes are found in endorheic basins or along the courses of mature rivers. In some parts of the world there are many lakes because of chaotic drainage patterns left over from the last Ice Age. All lakes are temporary over geologic time scales, as they will slowly fill in with sediments or spill out of the basin containing them.

Many lakes are artificial and are constructed for industrial or agricultural use, for hydro-electric power generation or domestic water supply, or for aesthetic or recreational purposes.